The joys of wet weather, when we got Baja I remember my OH calling up our trainer and telling her Baja had gone back to weeing inside, her answer..........I've had 15 other people call me this week with the same problem, its the rain!
We went out with him, treated him with high value rewards and eventually he got better. Now he's two and holds it in if its raining
Hope they all got on ok at the class